Lithium niobate is widely used in optical and photonic applications due to its excellent electro-optic, acousto-optic, and nonlinear optical properties. It is a key material in the fabrication of modulators for fiber-optic communications, where it enables high-speed signal modulation essential for data transmission over long distances.

It is also used in waveguides, optical switches, and frequency converters such as second-harmonic generators. Its piezoelectric characteristics make it suitable for surface acoustic wave (SAW) devices in mobile phones and other RF filters.

Additionally, lithium niobate is employed in quantum optics and integrated photonics research, including the development of photonic circuits and sensors. Its ability to manipulate light efficiently makes it valuable in laser technology and precision measurement systems.